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Call for Proposals for Cycle 3

The ALMA Director, on behalf of the Joint ALMA Observatory (JAO) and the partner organizations in East Asia, Europe, and North America, is pleased to announce the ALMA Early Science Cycle 3 Call for Proposals (CfP) for scientific observations that will be scheduled from October 2015 to September 2016.

The ALMA Observatory includes an array of fifty 12-m antennas for long baseline interferometric observations (the 12-m Array), and the Atacama Compact Array (ACA, also known as the Morita Array) composed of twelve 7- m antennas for short baseline interferometric observations (7-m Array) and four 12-m antennas for single-dish observations (Total Power or TP Array).

Cycle 3 observations provide an exciting opportunity for science from this unique world-class facility. They include standard and non-standard modes (see below). ALMA has entered into a phase where investigator-driven science observations dominate activities while continued improvements and developments are also explored.

Cycle 3 Capabilities

The Cycle 3 capabilities are:

  • At least thirty-six 12-m antennas in the main array, and ten 7-m antennas and two 12-m antennas (for single-dish maps) in the ACA.
  • Receiver bands 3, 4, 6, 7, 8, 9, & 10 (wavelengths of about 3.1, 2.1, 1.3, 0.87, 0.74, 0.44, and 0.35 mm, respectively).
  • Baselines up to 2 km for Bands 8, 9 and 10.
  • Baselines up to 5 km for Band 7.
  • Baselines up to 10 km for Bands 3, 4, & 6.
  • Both single field interferometry and mosaics.
  • Spectral-line observations with all Arrays and continuum observations with the 12-m Array and the 7-m Array. TP Array use is limited to spectral line observations in Bands 3 to 8.
  • Polarization (on-axis, continuum in Band 3, 6 and 7, no spectral line, no ACA, no mosaics, no circular polarization).
  • Mixed correlator modes (both high and low frequency resolution in the same observation).
  • The maximum observing time per proposal, as estimated by the OT, is 100 hours.

ACA observations are only available to complement 12-m Array observations for baselines up to 2 km, and are restricted to projects requiring detection of extended emission.

It is anticipated that about 2100 hours of 12-m Array time and ACA time will be available for the observations of Cycle 3 projects. This number of hours includes uncompleted grade A Cycle 2 projects that will be carried over into Cycle 3. Complete details are available in the Cycle 3 Proposer's Guide.

Standard and Non-Standard Mode Projects

Standard observing modes are those that have been used in previous Cycles and for which the data can be reduced by the pipeline. Data taken in standard observing modes will be pipeline-calibrated and imaged, their quality is assured by ALMA staff and will meet the standards set by the Observatory.

Non-standard modes are observing modes that are less well characterized, or for which the data need to be processed by ALMA staff. Up to 25% of the total observing time will be assigned to such projects. Non-standard modes include:

  • Band 8, 9 and 10 observations
  • Long baselines (> 2km)
  • Polarization
  • Spectral Scans
  • Spectral setups with all narrow band spectral windows (aggregate bandwidth < 934 MHz)
  • User-defined calibrations

Non-standard observing modes will be conducted on a best efforts basis, with the same meaning as in previous cycles. For these projects successful proposers will share risk with ALMA. ALMA staff will process the data and perform data quality assurance.

Data for all observing modes will be delivered by the ALMA Regional Centers (ARCs).

Array Configuration Schedule

During Cycle 3, the 12-m Array will be arranged in eight different configurations. The configuration schedule is given in the Proposer's Guide, and introduces limits to the observations in the following way:

  • High frequency projects (band 7, 8, 9, and 10) that can only be scheduled during the period December-February have a low chance to be observed even in the most compact configurations.
  • High frequency projects (band 7, 8, 9, and 10) that can only be scheduled during daytime are less likely to be observed due to the poorer atmospheric stability and higher system temperatures.

In Cycle 4 the array configuration schedule will be set to complement the Cycle 3 schedule (e.g. compact configurations will be done during the southern winter time for high-frequency observations).

Proposal Submission

The ALMA Science Portal at is the principal resource for scientific users. All proposals must be prepared and submitted electronically using the ALMA Observing Tool (OT) software. A LaTeX template is recommended for the preparation of the proposal scientific justification. Registration at the Science Portal is required for ALMA proposal submission.

The proposal submission deadline is 15:00 UT on April 23, 2015.

Proposers affiliated with a Chilean organization are required to submit additional supporting documentation to the ALMA Chilean Review Committee in order to qualify to use the Chilean share of ALMA time. See for detailed information.

Supporting Documents

All documents supporting this CfP are available at the ALMA Science Portal. Proposers are advised to consult the Learn More page and the Proposer's Guide. Additional useful information is available in the ALMA Technical Handbook and Early Science Primer.

Obtaining Help

For information not provided at the Science Portal, proposers may submit a Helpdesk ticket. Registration at the ALMA Science Portal is required for Helpdesk ticket submission.

Proposal Review

All proposals submitted in response to this CfP will be subject to peer review by an international committee. Proposals will be assessed on their scientific merit. Planned observations must be consistent with the Cycle 3 capabilities and must be fully technically justified.

Proposals will be checked for duplication, as defined by the Cycle 3 Proposer’s Guide, against Cycle 2 grade A projects (which have the highest priority of completion) or against Cycle 1 or 2 grade B or C projects that have archived data at the time of the Cycle 3 proposal deadline. The ALMA Proposal Review Committee will make recommendations regarding potential duplications.

Proposers may check for potential duplications in two ways: (1) by checking the ALMA archive which includes all Cycle 1 and 2 observations that have passed the first quality check ("QA0 Pass"); (2) by checking the list of all targets from Cycle 2 grade A projects that is linked to from the Science Portal ( All duplications must be justified. See Appendix B of the Cycle 3 Proposer's Guide for details.

Information for Proposers with undelivered data

Proposers of active Cycle 1 and Cycle 2 B- or C-graded projects should consider that these projects may not be completed before the end of Cycle 2. If they wish to observe the same targets in Cycle 3 they must specify whether or not the Cycle 3 observations will duplicate the former ones. If so, the proposers must specify if the duplicating observations need to be repeated in Cycle 3 even if they have been successfully completed by the end of Cycle 2. Such repetition, if deemed necessary, must be scientifically justified. 

Proposers may check the observational status of their Cycle 1 and 2 projects using the Project Tracker, available at the Science Portal.

Important dates

The key Cycle 3 dates follow. ALMA reserves the right to alter these dates.

24 March 2015 Release of CfP, OT and supporting documents
24 March 2015 Science Archive opens for proposal submission
23 April 2015 Proposal submission deadline, 15:00 UT
August 2015 Proposal Review Process outcome notification
October 2015 Start of ALMA Cycle 3 Science observations
September 2016 End of ALMA Cycle 3 science observations